Continuous rolling mill



y 22, 1952 J. w. SHEPERDSON 2,603,989

CONTINUOUS ROLLING MILL Filed March 5, 194' 3 Sheets-Sheet l & 22 22j'zz a] 22 g :f A igfgigf; 1' 3' q g INVENTOR.

JOHN W. JHEPE/PDS ON A TTORNEY y 22, 1952 J. w. SHEPERDSON 2,603,989

CONTINUOUS ROLLING MILL Filed March 5, 194' 3 Sheets-Sheet 2 O Il 33 34Fig. 5 32 Z9 E Fig.7-

- 60 INVENTOR.

JOH W, JHEPERDSON I I BY Zz 22 in the bar;

Patented July 22, 1952 CONTINUOUS ROLLING MILL John W. Sheperdson,Worcester, Mass., assignor to Morgan Construction Company, Worcester,Mass, a corporation of Massachusetts Application March 3, 1947, SerialNo. 732,034

3 Claims.

This invention relates to continuous rolling mills, and moreparticularly to continuous mills arranged for the hot rolling of metalbars and commonly known as merchant mills, although the invention may beapplicable in certainrespects to other types of continuous mills.

The usual merchant mill includes a plurality of roll. stands throughwhich the bar travels successively, the spacing and arrangement of theroll stands being such that the bar will extend through several or allof the stands simultaneously. It is customary to form a loop in the barbetween certain stands in order to relieve the bar of tension. If theloop is allowed to grow freely a considerable spacemust be provided toaccommodate such growth. Accordingly in some instances the size of theloop has been controlled by means of regulating apparatus actuatedautomatically by the looped bar itself. In general however such priorapparatus has been of a dellcate and flimsy construction likely to berendered It is a further object of the invention to provide a continuousrolling mill having a series of roll stands with looping tables betweensuccessive stands, and control apparatus for regulating the speeds ofthe roll stands in accordance with variations in the sizes of theadjacent loops, the

control apparatus being of a rugged construction which will beunaffected by mill scale and undamaged by cobbles.

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in 1 traveling from one roll stand to the next;

: Fig. 3 is a view similar to Fig. 2, showing the position of the partsafter a loop has been formed Fig. 4 is an enlarged section takenapproximately on the .line 44 of Fig.2;

Fig. 5 is an enlarged sectiontaken approximately on the line 5'5 of Fig.3;

Fig. 6 is an enlarged section taken approximately on the line 66 of Fig.2;

Fig. '7 is an enlarged section taken along approximately 0n the line1--"! of Fig, 2; and

Fig. 8 is an electrical wiring diagram showing a means for controllingthe speed of. one roll stand.

In Fig. 1' there is shown diagrammatically a plurality of roll standsIll, ll, I2, I3 and I4 arranged in a longitudinal row so that a metalbar may pass through them in succession. These roll stands are driven byelectric motors l6, l1, l8, I9 and 20 respectively. As shown, the roll 1standsare alternately horizontal and vertical, so

that, twistguides are not required. Between each pair of successive rollstands there is provided a substantially horizontal table 22 on which aloop may form in the bar, in order that the bar may be rolled withoutappreciable tension.

One of these looping tables 22 isshown on a larger scale in Figs. 2 and4. It will be seen that an upstanding flange 24 isformed on the tablealong the outer side of the path of the bar 3 as it travels in a directline from one roll stand I I to the receiving guide 25 of the followingroll stand B2. The table is preferably slightly inclined upwardly awayfrom this flange. On the inner side of the path of the bar there isprovided a row of guide blocks 26 which are arranged to project upwardlythrough openings 21 in the table. These blocks 26 are connected to oneanother beneath the table to form an integral unit or member 29. Thismember is provided with ears 30 (one only being shown) which arepivotally supported on a horizontal rod 3| (Fig. 4) beneath the flange24. An arm 32 extends downwardly from the member29', and a link 33connects this arm to the slidable piston rod 34 of a suitable fluidmotor 35. These parts are so constructed and arranged that after thefront end of the bar 3 has entered the roll stand l2, the member 29 maybe swung downwardly, asshown in Fig. 5, to

permit the bar to move over the topsof the blocks 26 and form a loop onthe table 22.

In order to assist in the formation of the loop, the flange 24 is shapedto provide a pocket 31 (Figs. 2 and 6) for the reception of a'yoke 38which carries an upright idler roller 39 positioned at the outer side ofthe path of the bar, near the entrance end of the looping table. Thisyoke 38 is pivotally supported by a vertical pin 40 beneath the table,and'the table is provided with an opening 4| within which the roller. 39may travel as the'yoke is moved about its pivot. Such move- Theinvention provides a means whereby the size of the loop in the bar willbe controlledautomatically. For this purpose the table22-'is" providedwith an opening 58 at the inner side of-the guide blocks 26. Within thisopening :there is mounted a group of electrical contact 1blocks'5l;

52, 53, 54, 55 and 56. These blocks are arranged in two rows extendingapproximately 'at'right angles with the path of travel of the bar, theblocks in one row being staggered with respect to theblocks. in theother row, and they project upwardly slightly above the" top of thetable so thatthe looped bare may make Contact with them.

Furthermore, the 1 blocks "in ,each' row slightly overlap the blocksin'the other row, in a direction lengthwise of.,the.rows,in, order thatthe bar'will alwayslbein contact with at least one block while the loopis under automatic control. 'Asfshown inFig. '7, the upper surfacesofthe blocks. are

rounded to avoid scratching of the bar. 'The blocks are electricallyinsulated from one another and from the table ,22', and for this purposeeach block is sl'ottedto fit 'overtheflupper portion of an upright plate'58 of electrical insulatingmaterial. ,The 'lower portions of the,plates are secured to beams .59 'whichzare connected to. the bottomjofthe table 22 by" suitable brackets 60.

Conduits 82 are provided ad'j'acent'thebeams' ,59 to enclosewires'leading to theseparatecontact blocks. Depending skirts6,3,areprovided onvthe blocks to'p'rotect the conduits from damage bycobbles and'to prevent sh'ortfc'ircuits by mill scale which may dropthrough=the opening'5ll. j'Itv will "be noted that the blocks". arespaced appreciably from one another and from the edge of the opetm so.

In Fig;- 8 there-is shown diagrammatically certain electrical apparatus"whereby the speed ,of the motor- I81 may "be controlled automatically,and it will be understood that'the's'peefds of ,the motors 11; 9 and20'may"be'controlled' by similar means. Theinormal speed ofeach motor issuch, in relation to the speed of the motor driving the precedingroll'stand} that: aloop "willflstart to *fo'rmandto increase in sizefassoonfasthejfront end of 'the' bar enters ther'rolls. The automaticcontrol simply prevents this? loop from growing beyond a predeterminedsize. "As jshownfthe motor I 8' is ofawell-knownty'rw havingan armature'fiiand a field fifi. ""lfhe armatureiliimay be connected to adirectcurrent. sourcef't'l through a 'switch'fifi. "The field 188 ma beconnected to. ,a

' "direct" current source" fisfthroiigh aiswitch "10. Resistance units12, I3,

4 The coils 88, 8|, 82, 83 and 84 also control normally open switches88b, 81b, 82b, 83b, and 84b respectively which are connected between theground at 81 and the respective contact blocks 5!, 52, 53, 54 and 55. Asindicated at 88, the bar B is grounded by its contact with the various-rol ls,:tables, and the like.

The operation of the invention will now be apparent from the abovedisclosure. The previously heated metal bar B will travel successivelythrough the roll stands [0, I I, l2, l3 and M, with -=a'-reduction inbar cross-sectional area taking place in each stand. Ordinarily the barwill exand close ;the switch 801). Opening the switch connected ,in-*series with" the I field 1 66, 1 but i.

size these units are allQshort-circuited. ,Forthis purpose there," areprovided. magnetic contactors having coils 19,80; 8|, 82. "Bland 84which ,conitrol normally closed switches 19a, 80a, 8461,8211, 83a, and34a respectively, :these switches being "connected .inishunt with theresistance units 12, 13, 14,15, lfifland ll respectively. 'Ihecoils l9,"88, 8 I, 82, 831; and .84 are connect'ed between a source ..86f..ofpositive electrical potential-and the respective contact. blocks 5 I,52. 53,54; 55and. 56.

the loopQ-inthebar has reached a predetermined tend through all of'theseroll stands during most of the rolling operation. As the front end ofeach bar leaves the roll stand I I and reaches the following 'table 2 2,as shown in Fig. 2, it will travel --in a straight path between theflange 24 on one side and the upwardly projecting blocks 26 on the otherside, thereupon passing through Fthejguide 25 and entering'the rollstand l2. As soon as'ithis occurs the operator will admit pressure fluidto the fluid motors 35 and 43, thereby lowering the guide blocks 28 (asindicated in 'Fig.

5) and swinging the idler roller 39 to the position shown in" Fig. 3,thereby forming a loop in the bar on the table 22. As the loop startsto' form, the motor 18 will be operating at a relatively low :speed,since the switches [90. to 84a inclusivewill I alljbe closed, thusshunting the resistance units 'lzf'to" 11, inclusive, and producing arelatively "strong field 66, the switches '68 and ill of course beingclosed. Accordingly the loop will continue toincrease insize and moveoutwardly across ,the 'table22. u'ntilit makes contact with the blockiland grounds the same. This will establish a circuit from the source 88through the coil 19 to ground, energizing this coil and opening theswitch 19a, therebyrendering the resistance unit 'l2'efiective to reducethe energization of the field {GB-and increasing the speed of the motor18 slightly. This will reduce the rate of growth or the loop, butordinarily itwill nevertheless corrtinue "to .grow'until it makescontact with the next block 52, grounding'thisblock and energizingthecoil 80. "Thiswill open the switch a -8fla-will"render the'resistanceunit 73 effective to speed up the motor [8 still further, and closingthe" switch -80b-willmaintain a circuit through ="the'-'coil 19 evenafter the loophas moved w'ardly out of contact with the block 5!. If theloop 'stillgcontinues to grow, it will make contact -With-the block 53and ground the sa'me,'thus "energizing the' coil 8| opening the switchI8la :and closingthe switch8lb. This will-render the resistance unit 14efiective toflincr'ease thespeed of the motor |8still further and at thesameti-me maintain-a circuit through-the coil 80 even afterthef'loop'has moved I outwardly out of-contact with thegblock 52.

I In. a similar .manner,-if the loop nevertheless continues to grow, itwillgrounclthe block 54,,then-the block .55, and possibly-eventhe.bl'ock156, which will result in shunting-all the resistance units 1'12to ll inelusivezand surely-provide sufiicientrspeed-for the-rolls I-2"toreduce the size of the'loop.

. Any appreciable reduction inthe 'size of {the loop will result-in aslowingrdown of the "rolls d2.

'Ihus if theloop moves inwardly out ofcontact withtheblock 56- andinto'contact-with the block -55,-the coil 84- will be de-energ'ized,"closing switch 84a and opening switch 84b. This will shunt thetresistancezunit 11 and cause a corresponding decrease in the speed io'ithemotor l8. -=O"peni-ng the switch 841) will ensure the de-energizationof the coil 83 in the event the loop moves inwardly out of contact withthe block 55. Thus any variation in the size of the loop will cause achange in the speed of the rolls I2 tending to oppose such variation,and the loop will remain within the size limits determined by thepositions of the inner and outer blocks 5| and 56 respectively.

As soon as the rear end of the bar has left the looping table, theoperator will restore the guide blocks 26 and the roller 99 to theiroriginal positions by means of the motors 35 and 43, in preparation forthe arrival of the next bar. The several looping tables 22 may all besimilar in construction and mode of operation.

It will be apparent that the invention provides a simple and dependablecontinuous rolling mill in which bars may be rolled without tension.Loops are formed between successive roll stands, and these loops arecontrolled by automatically varying the speeds of the roll stands. Thisautomatic control is brought about by engagement of the bar with contactblocks so arranged that the bar itself forms a portion of an electricalcontrol circuit. These blocks are constructed and mounted in a ruggedmanner, and they are very unlikely to be damaged by cobbles. Any loosescale which may drop from the bar as it travels across the blocks isfree to fall through the opening 50 in the table without causing shortcircuits or other difiiculties. The slight inclination of the table 22,shown in Fig. 5, is helpful in maintaining good electrical contact ofthe bar with the blocks.

Having thus described my invention, what I claim as new and desire tosecure by Letters Paten is:

1. A continuous rolling mill comprising a first and second roll standthrough which a metal bar may travel successively and thereby besubjected to successive reductions, a substantially horizontal loopingtable located between the roll stands, means to drive the roll stands atsuch relative speeds as to cause a portion of the bar to accumulatebetween the stands, means to deflect the portion of the bar between thestands in a lateral direction and thereby form a loop in the bar in asubstantially horizontal plane on the table, a series of stationaryblocks associated with the table and electrically insulated from thetable and from one another, the upper surfaces of the blocks beinglocated slightly above the upper surface of the table, the blocks beingin position to be engaged successively by the looped bar and thereby beelectrically grounded as the loop increases in size and the bar travelsover the tops of the blocks, means responsive to the grounding of thesuccessive blocks to alter the speed of one of the roll standssuccessively in a manner tending to limit the growth of the loop, aguide associated with said table for directing the bar toward the secondroll stand, and means retracting the guide to permit said loop to beformed by said deflecting means after the bar has reached the secondroll stand.

2. A continuous rolling mill comprising a pair of roll stands throughwhich a metal bar'may travel successively and thereby be subjected tosuccessive reductions, a substantially horizontal looping table locatedbetween the roll stands, means to drive the roll stands at such relativespeeds as to cause a portion of the bar to accumulate between thestands, means to deflect the portion of the bar between the stands in alateral direction and thereby form a loop in the bar in 'a substantiallyhorizontal plane on the table, a series of stationary blocks associatedwith the table and electrically insulated from the table and from oneanother, the upper surfaces of the blocks being in position to beengaged successively by the looped bar and thereby be electricallygrounded as the loop increases in size and the bar travels over the topof the block, and means responsive to the grounding of the successiveblocks to alter the speed of one of the roll stands successively in amanner tending to limit the growth of the loop, said table beingprovided with an opening to receive the blocks, the blocks being spacedfrom one another and from the edge of the opening so that mill scale mayreadily drop through the opening.

3. A continuous rolling mill comprising a pair of roll stands throughwhich a metal bar may travel successively and thereby be subjected tosuccessive reductions, a substantially horizontal looping table locatedbetween the roll stands, means to drive the roll stands at such relativespeeds as to cause a portion of the bar to accumulate between thestands, means to deflect the portion of the bar between the stands in alateral direction and thereby form a loop in the bar in a substantiallyhorizontal plane on the table, a series of stationary blocks associatedwith the table and electrically insulated from the table and from oneanother, the upper surfaces of the blocks being located slightly abovethe upper surface of the table, the blocks being in position to beengaged successively by the looped bar and thereby be electricallygrounded as the loop increases in size and the bar travels over the topsof the blocks, means responsive to the grounding of the successiveblocks to alter the speed of one of the roll stands successively in amanner tending to limit the growth of the loop, and a guide locatedbetween the direct line of bar travel from one stand to the other andthe stationary blocks, the guide providing a barrier to prevent lateralmovement of the bar toward the blocks, means being provided whereby theguide may be lowered after the front end of the bar has reached thesecond bar to allow formation of the loop.

JOHN W. SHEPERDSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,170,153 Henderson Feb. 1, 19161,443,223 Knight Jan. 23, 1923 2,193,189 Brooke et al. Mar. 12, 1940FOREIGN PATENTS Number Country Date 598,311 Germany u, June 8, 1934

